It has nothing to do with php. Just do what wrote in my previous post.
In a text editor open the files, e.g. wp-admin/edit-form-advanced.php
and go the the line 100. It will look something like this:
<div><textarea rows="<?php echo $rows; ?>" cols="40" name="content" tabindex="5" id="content"><?php echo $content ?></textarea></div>
then copy your text and insert it like this:
<div><textarea rows="<?php echo $rows; ?>" cols="40" name="content" tabindex="5" id="content"><?php echo $content ?><a target="_blank" href=""><img src="https://dinobaby.net/wp-content/" alt="Bods">
Text</a> From <a href="https://www.bodsforthemods.com " target="_blank">Bodsforthemods</a>
</textarea></div>
Save the file. You can do the same thing in the edit-form.php
if you are using the simple control for writing posts.